Search the Insulator Patent Reference Library:

Build your search criteria. The patent must match all the values specified.
Select patent types: Utility   Design   Reissue
Patent number:
Date:
Year between: and
Patentee starting with:
City:
State:
Assigned To starting with:
Description containing:
Category:
Class:    Subclass:
Click Search when complete:
SELECT DISTINCT patent.*, YEAR(date) as year FROM patent WHERE (category = 'Helical') ORDER BY date ASC, patent, type

Total of 3 patents found where: Category is 'Helical';

View a patent by clicking on the patent number. You can sort by any of the columns by clicking on the column name.

T / S Patent Date Description Patentee Category Assigned To
 1933
U 1,894,292 January 17, 1933 Strain Insulator
Helical strain insulator		 CRAMER, Walter
 Helical Locke Insulator Corp.
 1934
U 1,942,284 January 2, 1934 Electric Insulator
Helical grooves on top surface of suspension insulator		 HALTON, Geoffrey H.
 Helical Steatite & Porc. Prod. Ltd.
 1939
U 2,155,848 April 25, 1939 Insulator
Helical suspension & helical post type		 TAYLOR, John J.
 Helical The Ohio Brass Co.

Total of 0.00 seconds